1. Field of the Invention
The present invention relates to the technology field of alloy materials, and more particularly to a high-entropy superalloy.
2. Description of the Prior Art
Superalloy has become a high economic material for high temperature application because of possessing a variety of high-temperature mechanical properties. Besides being able to be long used under high temperature of above 650° C., various superalloys may also simultaneously exhibit other outstanding high-temperature mechanical properties such as high corrosion resistance, high creep strength, high wear resistance, high fatigue resistance, or high oxidation resistance under. The applications of superalloys are integrated and listed in following Table (1).
TABLE 1Needed high-temperaturemechanical properties forProducts in relatedApplication fieldthe applied superalloysapplication fieldAerospace Excellent high-Airplane engines, industrytemperaturegas turbine mechanical strengthengines, and engine valvesEnergy industryHigh oxidation andDesalination plants sulfidation resistanceand petrochemical pipelineselectronic High corrosion resistanceBattery housings, industryand thermal stabilitylead frames, and camera housings
Conventional superalloys are divided into iron-nickel based superalloy, cobalt based superalloy and nickel based superalloy, wherein the nickel based superalloy is one kind of traditional superalloy early developed, which is made by using nickel (Ni) as a primary elemental composition with a primary weight percentage in a range from 30 wt % to 50 wt % as well as adding a strengthening element such as Al, Co, Cr, Ti, or Nb into the nickel based superalloy for enhancing the creep strength. Moreover, it can further add at least one firebrick element into the nickel based superalloy for making the nickel based superalloy exhibit outstanding fatigue resistance and creep strength under high temperature; for example, Mo, Ta, W, Re, or Ru. However, resulted from all the firebrick elements belong to precious metals, the adding of the firebrick elements not only causes the manufacturing cost and selling price of the nickel based superalloy be too expensive, bus also limits the application scopes of the nickel based superalloy due to the costly selling price.
In view of the quality-price ratio of the traditional nickel based superalloy being too low, researchers and engineers skilled in the alloy developing and manufacturing field hence propose a nickel-iron based superalloy. The nickel-iron based superalloy is made by using two primary elemental compositions of nickel (Ni) and iron (Fe) as well as adding at least one trace element such as Al, Cr, Ti, or Nb into the nickel-iron based superalloy. On the other hand, some nickel-iron based superalloys also contain at least one solid solution strengthening composition, for instance, Mo, W, or Co. As the researchers and engineers skilled in the alloy developing and manufacturing field know, when using aluminum (Al) as the trace element added into the nickel-iron based superalloy, it must properly control the weight percentage of the aluminum to be less than 5 wt %. The reason is that at least one intermetallic phase not belonging to any precipitation strengthening phases would be produced in the internal of the nickel-iron based superalloy when the nickel-iron based superalloy simultaneously contains high content iron (Fe) and aluminum (Al) with the weight percentage exceeding 5 wt %. The most important is that the production of the intermetallic phase such as Ni2AlTi or Ni(Al, Ti) would decrease the high-temperature creep strength and the high-temperature mechanical properties of the nickel-iron based superalloy.
So that, resulted from both the traditional nickel based superalloy and the conventional nickel-iron based superalloy showing drawbacks and shortcomings in practical applications, the inventors of the present application have made great efforts to make inventive research thereon and eventually provided a high-entropy superalloy.